Microsoft knew prior to the Xbox 360’s launch that the console can damage discs if gamers tilt the unit while a disc’s spinning inside, documents from a lawsuit focused on the problem reveal.

The revelation was made by Hiroo Umeno, a Microsoft programmer, in an ongoing case that was filed with the Seattle District Court in July 2007. The plaintiffs are seeking class-action status on behalf of affected gamers, but the documents containing Umeno’s confession have only just been unsealed at the court, according to a report by website Seattle Tech.

The documents - seen by Register Hardware - state that the problem was initally discovered by Microsoft back in “September or October” of 2005. The console launched Stateside in November 2005.

After the 360's launch, Microsoft dispatched a team of engineers to retail stores across the US to investigate complaints that the console was scratching discs. It’s at this point that Microsoft determined that “if you tilt the [console] to the left or forward... you’ll cause a scratch”, it’s claimed in the documents.

Microsoft’s engineers, according to Umeno's testimony, found that scratches were caused by game discs becoming “unchucked” and colliding with the optical pickup unit. This action causes “deep circular rings” on discs.

It’s worth noting that Microsoft has already issued several ‘fixes’, including a disc replacement programme for gamers and a warning sticker placed on new Xbox 360s that tilting the console with a disc inside could result in disc damage.

Roughly 55,000 Xbox 360 owners had complained about scratched discs as of 30 April this year, according to the court documents. Several other lawsuits have also been launched against Microsoft from disgruntled gamers with scratched discs.